Azelastine is an anti-asthmatic medicinal agent having antiallergic and antihistaminic properties. Its chemical name is 4-(p-chlorobenzyl)-2-[N-methyl-perhydroazepinyl)(4)]-1-(2H)-phthalazinone. It has the following structural formula: ##STR1##
Azelastine and its salts with physiologically acceptable acids are effective primarily because of antihistaminic and antiallergic activity, but they also have a slight bronochospasmolytic effect.
.beta.-mimetics are medicinal agent with pronounced bronochospasmolytic activity. Examples of these compounds are: reproterol (7-{3[(.beta.,3,5-trihydroxyphenethyl)-amino]propyl}-theophylline), salbutamol, terbutaline fenoterol, procaterol, clenbuterol and orciprenaline.